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(N0 Model.) I 3 Sheess--Sheet` 1.

R. W.'HAMII.TON. DIRECT ACTING DPLEX P UMPING ENGINET Y eb Patented I' Boe man/LEZEN@ 3 Sheets-Sheet A2.

(No Model.)

R. W. HAM1LToN-` DIRECT ACTING DUPLEX PUMINGf ENG-INE.

. Patented lieb. 12, 1834.

NoI 293,243

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l ROBERT V. HAMILTON, OF HARTFORD, CONNECTICUT, ASSIGNOR OF TWO- THIRDS TO MARSHALL T. DAVIDSON, OF BROOKLYN, N. Y.

yDIRECT-ACTING DUPLX PUMPINiG-ENGINE.

SPECIFICATION forming part of Letters Patent No. 293,243, dated February 12, 1884. Application led September 8, 1883. (No model.)

To all whom t may concern:

Be it known that I, ROBERT TV. HAMILTON, a citizen ofthe United States, residing at Hartford, in the county of Hartford and State of l Connecticut, have invented certain new-and useful Improvements in Direct-Acting Duplex Pumping-Engines; and I do hereby declare the following to be a full, clear, and exact description of theinventiou, such as will enable others skilled in the art to which it appertains to make 4and use the same. This invention relates to that class of directacting duplex pumping-engines which can be instantly converted into two independentpumping engines without requiring any change in the mechanical connectionsof the valve-gears.

My improvement consists, mainly, in providing each engine with a supplemental valve operated by the other engine for governing the supply of live steam to the induction-valve of the chest-piston of its own engine, said supplemental valve being so constructed and arranged that it may give, at the will of the engineer, either a ,continuous supply to both steam-cavitiesof said induction-valve, or an intermittent supply alternately to one steamcavity and the other thereof.

In order that my invention may be clearly understood, I have illustrated in the annexed dra-wings, and will proceed to describe, one form thereof which I have put into practical and successful use.

Figure 1 is an end view of a duplex pumping-engine embodying my improvements, drawn partly in elevation and partly in section, the planes of the section being indicated by broken lines ma" and y y of Fig. 2. Fig. 2 is a side elevation thereof, seen from a plane indicated by the broken line Z Z of Fig. 1. Fig. 3 is a longitudinal section of one of the engines. Figs. 4 to llare detail views, Figs. 4, 5, 6, and 8 being drawn on a larger scale than the other iigures.

The same letters of reference indicate identr cal parts in all the figures.

I applied my invention to a pair of what are known in the market `as fDavidsons ,pumping-engines,7 which are provided with Vof said chest-cylinder, terminating in a port-- valves substantially such las described in H. A. Jamiesons United States Letters Patent No. 155,728; and in applying my invention to 'such pumping-engine I found it convenient to govern the admission of live steam to the chest-piston by a separate induction-valve, insteadl of using the main slide-valve for that purpose, as described in the aforesaid patent. The main slide-valve is used, however, as before, to govern the exhaust from the chestcylinder, and the induction valve, though separated from the main slide-valve, moves in unison therewith. The pin a., by which the main slide-valve A is mechanically oscillated and given its initial endwise movements, is elongated upward and carries at its upper end 6 5 the separate induction-valve B, which is seat- L ed against the'upper side of the chest-cylinder. A spring, c', encircling the pin a between the main slide-valve and the induction-valve B, may be used to hold both valves firmly to their seats. The two wings of the main slide- `Valves are provided with cavities a2 and a, respectively. The cavity ci is adapted to cou nect the inner port of a channel, c, in the wall of the chest-cylinder with the exhaust 7 5 port c. The inner portof 'the channel c is located near the middle of the chest-cylinder, and the channel c runs from there to one end opening behind one head of the double-headed piston. The inner port of the channel c2 is also located at about the middle of the chestcylinder; but the channel c2 runs from there to the opposite end of the chest-cylinder and terminates in a port opening behind the other head of the double-headed piston. The channels c c2 are used only for exhausting the steam from either end of the chest-cylinder. Live steam to operate the double-headed chest-piston is admitted to one end of the chest-cylinder through the channel b in the upper part of the wall thereof. Live steam is admitted to the other end of the chest-cylinder through a channel, b3, in its wall. The channels b and b3 extend from the opposite ends of thechestcylinder to about the middle thereof,`and terminate in ports whichv are controlled by the induction-valve B. As the inductionfva-lve is shifted back and forth, it alternately closes the inner port of the channel b and puts said port in communication, through cavity b', with the steam-port b2 in the top of the chest-cylinder.

In like manner is the inner port of channel b alternately closed by the induction-valve B and put in communication, through cavity b", with the steam-port b5 in the top of the chest-cylinder. rIhus the induction-valve admits live steam alternately to the respective ends of the chest-cylinder, to drive the chestpiston for completing the throw of the main slide-valve. The engines Nos. l and 2 are constructed precisely alike, with the exception that the means for mechanically starting the valves so far described are arranged reversely to each other, so that the connections from the valves to the cross-heads are located at the remote sides of the two engines. Steam fromthe boiler enters the chest-cylinder, between the heads of its double-headed piston, through the pipe G, and has free communication at all times with a supplemental valvechest, D, placed on the top of the chest-cylinder, through the large port G2 in the top of the chest-cylinder;

It will be observed that while I have made a structural change in the valves for admitting live steam to the respective ends of the chest-cylinder and exhausting spent steam therefrom, the operation of the valves does not differ in any essential particular from that of the valves described in the aforesaid Ja- 'mieson patent; furthermore, that each engine is capable of working as an independent engine so long as the ports b2 b5 remain constantly open.

In order that the engines may be worked duplex as well, I provide each with a supplemental valve, E, fitted to oseillate in the supplemental valve-chestD, to close and open the steam-ports b2 and b5 alternately when held in one of two positions, and to constantly keep said ports uncovered when shifted to the other position. The construction of this supplemental valve, which governs the supply of steam to the induction-valveof the chest-cylinder, is shown in plan view and cross-section in Fig. 8. It is essentially a cylinder, the central portion of which is reduced, so that steam entering through port Clean freely circulate around it, and it is also provided with a longitudinal groove, e, extending from end to end, so that steam can also freely pass to each end of the valve. rIhe cylindrical ends of this supplemental valve are provided with longitudinal grooves, (marked e c2, respectively,) so arranged that by oscillating the valve said grooves may alternately register with the ports b2 and b5, and thus alternately admit steam to said ports. One end of this valve is connected to a stem, E, which passes through a stuffing-box, and is at its outer end pivoted to the short arm of the hand-lever E2, fulcrumed on-a bracket-arm, E3, secured to one head of the 'valve-chest D. By means of the handlever E2 the valve E may be slid in its chest so as tov occupy the position shown in Figs. l and 4, in which position the valve is adapted to alternately open and close the ports b2 and b5; or it may be shifted to the position shown in Fig.v5, in which position the ports b2 and b remain constantly open. the supplemental valve is provided with a rectangular hole, which is entered by the rectangular end of the collared stem F, which passes through the other head of chest D, and has secured to its outer end a downwardlyprojecting arm, F, which is connected by .a rod, F2, to the upper outer en'd of an arm, FJ. The arm F3 of engine 2 is secured to the solid cross-shaft G, which is journaled in suitable bearings formed on or mounted upon the main' cylinders ofthe two engines. The arm l? of engine l'is secured to a hollow shaft, H, tted to turn loosely on thesolid shaft G.

To the solid shaft G is secured an arm, G, which is connected by a rod, G2, to one of the cross-heads G3, keyed to the piston-rod I of engine l.

To the hollow shaft H is secured an arm, H', which is connected by a rod, H, to one end of the cross-head H3 of the piston-rod K of engine 2. Thus it will be observed that the supplemental valve E of engine 2 is oscillated by connections from the piston-rod of engine l, and the supplemental valve E of engine 1' by connections from the piston-rod of engine 2. The engines are so timed with respect to each other that the supplemental valve E of one engine is ready to close one of the ports b2 and b5 and open the other at about the middle of the stroke of the main piston of the other engine. A pair of engines thus constructed may be used duplex, or may be made to work independently, at the pleasure of the engineer, it being only necessary to shift the hand-levers E2 to change from duplex to single, and vice versa. Vhen the engines are working independently, the supplemental valves merely oscillate in their chests without producing any effect. y

It is not absolutely necessary to provide each engine with a supplemental valve for governing the supply of steam to the induction-valve of its chest-cylinder, since where only one of the engines is provided with such a valve .the two engines may still be worked either duplex or independently; but I prefer the described use of a supplemental valve for each-engine for various reasons, among which I may cite that the engines are then both under positive control when working duplex, and that the capability of the engines of working duplex is still preserved in case one of the supplemental valves or its gear gets out of repair.

I believe that I am the rst to use in apair of direct-acting engines a supplemental valve for governing the induction of steam behind the chest-piston, and operating said supplemental valve from the piston-rod of the other engine, and therefore do not confine myself The other end of l IOO IIO

primarily tothe details of construction here inbefore setforth, which may be greatly Varied Without changing the essential character istie of my invention. For instance, the snpplemental Valve may be a sliding instead of an oscillating Valve, other'necessary changes being made to suit the altered conditions. The connections from the piston-rod of one engine to the stem of the supplemental valve of the other engine may be modified in Various Ways.

Y 'Ihe supplemental valve may be shifted by a screw and hand-wheel.

Havingthns described my invention, I claim isl. In a duplex engine, the combination, substantially as before set forth, of asupplemental valve for governing the supply of steam to the induction-valve of the chest-cylinder of one engine and the piston-rod of the other engine.

what

293,243` u r i s 2. In a duplex engine, the combination, substantially as before set forth, ofthe piston-rod 'of one engine and a supplemental valve for lgoverning the supply of steam to the induetion-valve of the chest-cylinder of the other engine, said supplemental valve being shiftable by hand at pleasure from a position in which it opens and closes the ports to the inductionyalve alternately to a position in which said ports remain constantly uncovered, and vice versa.

In testimony whereof I afiix my signature lin presence of twowitnesses.

ROBERT. W. HAMILTON.

Vitnesses:

F. H. SAWTELLE, LoUIs E. MARsHALL. 

